Magic embryology: guidance by electric fields (Introduction)

by David Turell , Friday, January 17, 2025, 18:21 (50 days ago) @ David Turell

Using electric forces:

https://phys.org/news/2025-01-cues-cells-harness-electric-fields.html

"As an embryo grows, there is a continuous stream of communication between cells to form tissues and organs. Cells need to read numerous cues from their environment, and these may be chemical or mechanical in nature. However, these alone cannot explain collective cell migration, and a large body of evidence suggests that movement may also happen in response to embryonic electrical fields. How and where these fields are established within embryos was unclear until now.

"'We have characterized an endogenous bioelectric current pattern, which resembles an electric field during development, and demonstrated that this current can guide migration of a cell population known as the neural crest," highlights Dr. Elias H. Barriga, the corresponding author who led the study published in Nature Materials.

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"The neural crest is an essential part of the embryo, and this region of cells forms the bones of our face and neck, as well as parts of the nervous system. Dr. Barriga and colleagues found that cells of the neural crest are directed by internal electric fields during development, much like drivers follow the signals of a traffic warden.

"The group discovered that through this process, known as electrotaxis, cells can sense direction from electric fields generated inside the embryo and move accordingly. This observation had been previously limited mostly to the study of cultured cells, but has now been demonstrated within a developing embryo. But an important question remained unanswered: How are the cells interpreting these currents and translating them into directional movement?

"To answer this question, Dr. Barriga and his team identified an enzyme known as voltage-sensitive phosphatase 1 (Vsp1) found in neural crest cells. Due to the versatile structure of Vsp1, it seemed capable of both sensing and transducing electrical signals. To confirm that Vsp1 is required for electrotaxis, the researchers created a defective version of the enzyme and showed that collective electrotaxis was impaired in cells injected with this copy.

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"Contrary to expectations, Vsp1 did not appear to be relevant for movement itself, but instead could specifically convert electric current gradients into directional and collective migration. This is a unique observation, as most enzyme sensors are required for movement itself, making it difficult to study their role in guiding direction.

"Going one step further, the authors also proposed how the electric fields may form: through mechanical stretching of a region known as the neural fold. As the cells in this region stretch, this causes activation of specific ion channels, resulting in a voltage gradient. Then, when cells encounter this gradient, Vsp1 transforms the electrical signals into a directional cue, telling the cells which way to go, and collective cell migration results.

"This is the first experimental evidence to suggest that electric fields emerge along the path where neural crest cells migrate, and to explain their mechanism of origin. These discoveries highlight a valuable contribution that bioelectricity provides during embryonic development. By advancing our knowledge of electrotaxis within a living animal, this research opens new possibilities for mimicking developmental processes in the lab, with accuracy greater than ever before.

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"'In a broader perspective, we have now introduced another player into the intricate process of tissue morphogenesis" says Dr. Barriga. "The question is now, how does this fit into already established frameworks of mechanical and chemical cues during embryogenesis?".

"Beyond development, similar mechanisms might also exist during wound healing and cancer progression. Understanding how electric fields guide cell migration could even inspire potential novel strategies in tissue engineering and regenerative medicine. However, further research is required to expand on the role of electric fields in cellular behavior, and increase our understanding of the physics behind living systems."

Comment: the use of electric fields to control growth of tissue is a fascinating addition to the mechanical and other forces recognized at work in forming a whole organism. Not desvoloped by step-by-step changes from random mutations. Strong evidnece of design.